Magnets and ATEX
Magnetic systems for use in explosive environments
The ATEX Directive (ATEX: ATmospheres EXplosibles) is a European regulation aimed at ensuring a high level of protection for workers and for the environment where explosive atmospheres are present or may be present.
ATEX Directive 2014/34/EU is intended for equipment manufacturers and describes the requirements for designing, manufacturing and marketing equipment and protective systems intended for use in potentially explosive environments. The directive provides guidance as well as standards to ensure that equipment cannot be a source of ignition and can be used safely in explosive environments.
Directive 1999/92/EC is intended for users and serves to protect workers from the risks to which they are exposed in explosive conditions in the workplace. The directive requires employers to assess and control potential risks, take appropriate safety measures and adequately instruct workers.
Within ATEX, a distinction is made between gas and dust environments. Many magnetic separation applications take place in dust environments.
Areas with a risk of explosion are subdivided into various zone categories, depending on the frequency of potentially explosive conditions. We divide equipment suitable for use in ATEX zones into three categories: 1, 2 and 3. These correspond to the protection levels: very high, high and normal.
Prevent dust explosions
Preventive measures against dust explosions
Magnets and metal detectors can be used to help prevent mechanical sparks and the ensueing dust explosions. Please read the article "Prevention of dust explosions in the food industry", chapter 4. Solids processing / Milling and grinding (article by HSE - Health and Safety Executive of British Government).
There are several measures that must be taken to decrease the chance of dust explosions:
- prevention of mechanical sparks and static electricity
- temperature sensing and RPM monitoring on machines
- enforcement of low dust concentrations
- prevention of dust clouds and dust layers
- inertion by powdered additives
- inertion by gaseous additives
- use of an automatic sprinkler installation
- the prevention of smolder and spontaneous ignition
Mechanical sparks can be prevented by using sieves, magnets and metal detectors on the raw materials. This helps monitor the materials and removes unwanted particles.